Luckily for you, viking clothing from throughout the portions of the middle ages and all over the parts of Europe in which vikings were active is well researched and documented and used pretty heavily in foamfighting.
The basis of all good viking garb is a pair of relatively tight pants, leg wrappings, and a long tunic. Everything else is pointing you towards either a specific group (the wider pants of certain Danish groups, certain middle eastern features of the Varangians, Rus influences) or is just getting better at viking garb: an overtunic to go over your linen undertunic, viking-style coats, a 6-panel hat, woven cloth belts, that sort of thing.
As far as armor goes, it's sort of up to you; I believe I've heard rumors that there is no evidence of gambesons being worn by viking-types (seems they would just wear a couple of thick wool tunics and call it good enough). Maille was certainly the most common body armor; a (relatively simple) helmet would have been even more common. There are some reenactors or varying grades of authenticity that wear lamellar klibanions or cuirasses of different sorts, as well.
Good viking garb in period fabrics fits Belegarth's garb requirements beautifully and fights extremely well.
Hopefully this thread will attract some of the real experts on viking stuff around here: Brenna, or the Ilsa/Alric team seems to know their stuff, too.
An article on viking men's clothing:
http://www.cs.vassar.edu/~capriest/mensgarb.htmlA great tutorial on a simple design of kyrtle or tunic from slightly later in time, but which looks great for viking personas:
http://www.dagorhir.com/gear/content/ga ... _tunic.php Make one out of linen and one of wool and you're in great shape. (Oh, and: The armpit gussets should be more like 5" square, not 10" square.)
Here's a way to finish the neckline that is sort of classically viking in the popular mind:
http://www.dagorhir.com/gear/content/ga ... facing.pdfTailored Tunics, Ilsa's garb company, myself, and several others make viking-style garb for sale, as well, either custom or off-the-rack.
Oh, and, winingas (the leg wraps):
http://www.rosieandglenn.co.uk/TheLibra ... ndings.htm I typically just wrap once around my leg just below the knee, then spiral down to my ankle quickly (one wrap, basically), then spiral up my calf just barely overlapping the wrap and hook it to itself at the top just below my knee. Ilsa at Tailored Tunics sells 'em, Historic Enterprises sells 'em, Googling "winingas wrappings" gets you a few more suppliers. They're mostly just 4"-wide 9 yd long strips of herringbone wool, partially fulled and zig-zagged on the edges to keep them from raveling.
RE Cost: Linen and wool can be got for reasonable prices nowadays, especially if you wait for sales on the fabrics at sites like fabricmartfabrics.com or
http://www.fabrics-store.com/ and they're way more comfortable when sweating than polyester, poly-cotton, or even plain cotton. You only need between 2 and 3 yards of ~58" wide fabric for any given tunic and a bit less for most pants patterns. 3-4 yards gets you a coat and 4 is typically plenty for any given viking-era cloak. A good six-panel hat can be made from 1/3 yd or less or fulled coating wool bought as a remnant from Jo-Ann's or as leftovers from an overtunic, washed and dried on hot several times to full it up some more.
Armor is gonna be where you run into your cost and practicality problems. Good riveted maille is expensive and butted maille is even heavier than riveted, though cheaper and less accurate.
Good luck!